Ten-year efficacy and safety of tenofovir disoproxil fumarate treatment for chronic hepatitis B virus infection.

BACKGROUND & AIMS: Tenofovir disoproxil fumarate (TDF) is a first-line treatment for chronic hepatitis B (CHB). We aimed to describe the efficacy and safety profiles of TDF treatment for up to 10 years in a well-described cohort of CHB patients. METHODS: Hepatitis B e antigen (HBeAg)-negative and HBeAg-positive patients from two randomised, double-blind trials (ClinicalTrials.gov: NCT00117676 and NCT00116805) completed 48 weeks of randomised treatment with TDF or adefovir dipivoxil. A subset of these patients was then eligible to receive open-label TDF treatment for up to 10 years. At Year 10, patients were assessed for virological suppression, alanine aminotransferase (ALT) normalisation, serological response, safety and tolerability. RESULTS: Of 641 randomised and treated patients, 585 (91%) entered the open-label extension phase with 203 (32%) patients completing Year 10 of the study. At Year 10, 118/118 (100%) of HBeAg-negative patients and 78/80 (98%) of HBeAg-positive patients with available data achieved hepatitis B virus (HBV) DNA < 69 IU/mL, while 88/106 (83%) and 60/77 (78%) patients achieved ALT normalisation, respectively. Of the 23 patients with HBeAg status available at Year 10, 12 (52%) and six (27%) experienced HBeAg loss and seroconversion, respectively. No resistance to TDF was documented up to Year 10. In the period between Year 8 and Year 10, the safety profile of TDF was similar to previous reports, with few patients experiencing renal- or bone-related adverse events. CONCLUSIONS: Over 10 years, TDF had a favourable safety profile, was well tolerated, and resulted in continued maintenance of virological suppression with no documented resistance.

Correction to: Hepatitis B Surface Antigen Loss with Tenofovir Disoproxil Fumarate Plus Peginterferon Alfa-2a: Week 120 Analysis.

The original version of this article unfortunately contained affiliation and textual errors. This has been corrected with this erratum.

Hepatitis B Surface Antigen Loss with Tenofovir Disoproxil Fumarate Plus Peginterferon Alfa-2a: Week 120 Analysis.

BACKGROUND AND AIMS: Hepatitis B surface antigen (HBsAg) loss is the ideal clinical endpoint but is achieved rarely during oral antiviral treatment. A current unmet need in CHB management is achievement of HBsAg loss with a finite course of oral antiviral therapy, thereby allowing discontinuation of treatment. Significantly higher rates of HBsAg loss at 72 weeks post-treatment have been demonstrated when tenofovir disoproxil fumarate (TDF) was combined with pegylated interferon (PEG-IFN) for 48 weeks compared with either monotherapy. This analysis provides follow-up data at week 120. METHODS: In an open-label, active-controlled study, 740 patients with chronic hepatitis B were randomly assigned to receive TDF plus PEG-IFN for 48 weeks (group A), TDF plus PEG-IFN for 16 weeks followed by TDF for 32 weeks (group B), TDF for 120 weeks (group C), or PEG-IFN for 48 weeks (group D). Efficacy and safety at week 120 were assessed. RESULTS: Rates of HBsAg loss at week 120 were significantly higher in group A (10.4%) than in group B (3.5%), group C (0%), and group D (3.5%). Rates of HBsAg loss and HBsAg seroconversion in group A were significantly higher than rates in group C (P < 0.001 for both) or group D (HBsAg loss: P = 0.002; HBsAg seroconversion: P < 0.001). CONCLUSIONS: The results of this analysis confirm the results from earlier time points which demonstrate the increased rate of HBsAg loss in patients treated with a finite course of PEG-IFN plus TDF compared with the rates in patients receiving either monotherapy.

Long-term response after stopping tenofovir disoproxil fumarate in non-cirrhotic HBeAg-negative patients - FINITE study.

BACKGROUND & AIMS: There is currently no virological cure for chronic hepatitis B but successful nucleos(t)ide analogue (NA) therapy can suppress hepatitis B virus (HBV) DNA replication and, in some cases, result in HBsAg loss. Stopping NA therapy often leads to viral relapse and therefore life-long therapy is usually required. This study investigated the potential to discontinue tenofovir disoproxil fumarate (TDF) therapy in HBeAg-negative patients. METHODS: Non-cirrhotic HBeAg-negative patients who had received TDF for ≥4years, with suppressed HBV DNA for ≥3.5years, were randomly assigned to either stop (n=21) or continue (n=21) TDF monotherapy. Standard laboratory tests including HBV DNA viral load, HBsAg and alanine aminotransferase (ALT) measurements, and adverse event reporting were carried out during treatment and post-treatment follow-up for 144weeks. RESULTS: Of the patients who stopped TDF therapy, 62% (n=13) remained off-therapy to Week 144. Median HBsAg change in this group was -0.59log10IU/ml (range -4.49 to 0.02log10IU/ml) vs. 0.21log10IU/ml in patients who continued TDF therapy. Four patients (19%) achieved HBsAg loss. Patients stopping therapy had initial fluctuations in viral load and ALT; however, at Week 144, 43% (n=9) had either achieved HBsAg loss or had HBV DNA <2,000IU/ml. There were no unexpected safety issues identified with stopping TDF therapy. CONCLUSIONS: This controlled study demonstrated the potential for HBsAg loss and/or sustained virological response in non-cirrhotic HBeAg-negative patients stopping long-term TDF therapy. Lay summary: Nucleos(t)ide analogue (NA) is usually a life-long therapy for HBV patients. This randomised controlled study investigated the discontinuation of tenofovir disoproxil fumarate (TDF) therapy in HBeAg-negative patients. Of the patients who stopped TDF therapy, 62% remained off-therapy to Week 144, of which 43% of patients had achieved either HBsAg loss or HBV DNA <2,000IU/ml. This offers a potential for long-term HBV-suppressed patients without cirrhosis to stop NA therapy under strict surveillance. Clinical trial number: NCT01320943.

Risk of hepatocellular carcinoma in treatment-naïve chronic hepatitis B patients receiving tenofovir disoproxil fumarate versus entecavir in the United States.

BACKGROUND: Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are the first-line treatment agents for chronic hepatitis B virus (HBV). Recently, whether the degree to which the risk of hepatocellular carcinoma (HCC) may be reduced by ETV vs TDF has been debated. We compared the incidence of HCC among treatment-naïve patients receiving TDF vs ETV in the United States. METHODS: From a large administrative medical claims database of commercially insured patients, we identified 166,933 adults with a diagnosis of chronic hepatitis B and a minimum of 12 months of prior enrolment, of whom 3934 and 6127 initiated ETV and TDF respectively. Fine-Gray hazard regression models incorporating treatment propensity scores (PS) were used to estimate the risk of HCC incidence associated with TDF vs ETV; variables considered for adjustment included demographic characteristics, concomitant medication use and baseline comorbidities, as well as competing events including liver transplantation and medication changes. RESULTS: After PS weighting, the TDF and ETV groups were well-matched. During the follow-up, 90 patients developed HCC, including 50 receiving ETV and 40 receiving TDF, giving rise to crude incidence rates of 0.62 per 100 person-years (PY) and 0.30 per 100 PY respectively. In PS-weighted, multivariable analysis, TDF was associated with a subdistribution hazard ratio for HCC of 0.58 (95% confidence interval [CI]: 0.38-0.89) compared to ETV. Results were similar when patients ≥40 years and men and women were analysed separately. CONCLUSION: Among commercially insured, treatment-naïve patients with chronic hepatitis B in the United States, treatment with TDF was associated with significantly lower risk of HCC than ETV.

Treatment with tenofovir disoproxil fumarate or entecavir in chronic hepatitis B virus-infected patients with renal impairment: results from a 7-year, multicentre retrospective cohort study.

BACKGROUND: Limited data exist regarding tenofovir disoproxil fumarate (TDF) safety and effectiveness in chronic hepatitis B virus-infected (CHB) patients with renal impairment (RI). AIMS: To compare real-world data on renal safety and effectiveness of TDF vs entecavir (ETV) in CHB patients with moderate-to-severe RI. METHODS: Retrospective, non-interventional, cohort study analysing medical records for TDF/ETV-treated CHB patients (54 European centres). Included patients experienced moderate-to-severe RI (creatinine clearance 20-60 mL/min [Cockcroft-Gault]) either before TDF/ETV initiation ('before' subgroup [baseline = treatment initiation]) or after TDF/ETV initiation ('after' subgroup [baseline = first RI occurrence]). The primary objective was TDF safety, particularly renal-related adverse events of special interest (AESI). TDF and ETV safety and effectiveness were compared and multivariate analyses were performed using inverse probability treatment weighting. RESULTS: 'Before' subgroup included 107 TDF- and 91 ETV-treated patients; 'after' subgroup included 212 TDF- and 77 ETV-treated patients. Mean baseline creatinine clearance was higher for TDF- vs ETV-treated patients (both subgroups). Median follow-up was 3.1 years (both treatments). AESI were more frequent with TDF vs ETV ('before': 18.7% vs 8.8%; 'after': 9.9% vs 3.9%); however, differences were not significant by multivariate analysis. Only TDF-treated patients experienced renal tubular dysfunction (6.5% 'before'; 1.9% 'after') as well as renal adverse events leading to treatment discontinuation (8.4% 'before'; 7.1% 'after'). Effectiveness was similar between treatments. CONCLUSIONS: Overall safety was similar for TDF vs ETV (both subgroups). Given that renal tubular dysfunction occurred with TDF and not with ETV, renal safety concerns may be greater with TDF in CHB patients with RI.

Safety and efficacy of stopping tenofovir disoproxil fumarate in patients with chronic hepatitis B following at least 8 years of therapy: a prespecified follow-up analysis of two randomised trials.

BACKGROUND: Effective and well tolerated nucleos(t)ide analogue treatment exists for patients with chronic hepatitis B, although treatment is generally anticipated to be life-long, with concomitant costs and treatment-related side-effects. We aimed to characterise the outcomes of patients with persistent viral suppression who discontinued nucleotide analogue use after extended treatment. METHODS: The primary objective of this prespecified analysis was to evaluate the safety of stopping long-term tenofovir disoproxil fumarate therapy in patients enrolled in two (completed) randomised controlled studies, GS-US-174-0102 (ClinicalTrials.gov, number NCT00117676) and GS-US-174-0103 (ClinicalTrials.gov, number NCT00116805). In those studies, patients who had completed 8 years or more of nucleotide analogue treatment, were hepatitis B surface antigen (HBsAg)-positive with hepatitis B virus (HBV) DNA concentration of less than 29 IU/mL, and were unwilling or unable to continue therapy were required by protocol to enter a 24-week treatment-free follow-up (TFFU) phase. We present data for patients in the TFFU phase who were assessed at baseline and monitored every 4 weeks for changes in qualitative serum HBsAg, HBV DNA, and alanine aminotransferase (ALT) concentrations in addition to standard safety assessments. FINDINGS: Of 124 patients who entered the TFFU phase, 54 (44%) patients did not complete 24 weeks of follow-up (median 12 weeks; IQR 0-20). Overall, 32 (26%) patients reported an adverse event. Serious adverse events occurred in five (4%) patients, including elevated ALT concentrations in two patients, hepatic flare in two patients, and increased lipase in one patient. 38 (31%) of patients had grade 3 or higher laboratory abnormalities, the majority of which were ALT elevations (36 patients). Of the 106 hepatitis B e antigen (HBeAg)-negative patients who entered the TFFU phase, 63 (59%) were followed for 24 weeks. HBsAg loss was observed in five (5%) of the 106 HBeAg-negative patients who entered the TFFU phase, and 37 (35%) had both HBV DNA concentrations of less than 2000 IU/mL and ALT concentrations less than the ULN at TFFU week 24. 18 HBeAg-positive patients entered the TFFU phase, of whom seven (39%) were followed up for 24 weeks. Of these seven patients, none had HBsAg loss or HBV DNA of less than 2000 IU/mL and one (14%) had an ALT less than the ULN at week 24. INTERPRETATION: Within 24 weeks of stopping 8 years or more of nucleotide analogue therapy almost a third of patients experienced a grade 3 or higher laboratory abnormality. Although few patients achieved HBsAg loss, a subgroup of HBeAg-negative patients can achieve a low-replicative state within a short duration of follow-up. FUNDING: Gilead Sciences, Inc.